If a person suffers from a urinary incontinence, specifically if a person suffers from a stress urinary incontinence, then urine leakage can be caused by application of abdominal pressure during normal exercise or by laughing, coughing, sneezing or the like. The cause of this may be, for example, that the pelvic floor muscle which is a muscle for supporting the urethra is loosened by birth or the like.
For the treatment of urinary incontinence, a surgical treatment is effective, in which there is used, for example, a tape-shaped implant called a “sling.” The sling is indwelled inside the body and the urethra is supported by the sling (see, for example, Japanese Application Publication No. 2010-99499). In order to indwell the sling inside the body, an operator would incise the vagina with a surgical knife, dissect a region between the urethra and the vagina, and make the dissected region and the outside communicate with each other through an obturator foramen using a puncture needle or the like. Then, in such a state, the sling is indwelled into the body.
In the prior art, however, it is necessary to largely incise and greatly dissect biological tissue in order to indwell the sling. This is rather invasive on the patient and leads to a heavy burden on the patient.
On the other hand, as an instrument for dissection or separation of a biological tissue, there has been proposed a dissector having an expansion part which is expandable (see, for example, Japanese Application Publication No. 2007-160085). In the dissector, the expansion part is disposed in a region for dissection or separation of a biological tissue inside the body, and thereafter the expansion part is expanded. The expansion part in the expanded state is then moved while keeping contact with the biological tissue inside the body, thereby dissecting the biological tissue.
In this dissector, however, the expansion part in the expanded state is moved while keeping contact with the biological tissue. Therefore, the friction between the expansion part and the biological tissue is great, making it difficult to smoothly dissect the biological tissue. In addition, the invasiveness to the patient is great and the burden on the patient is heavy.